stem, staged fuel injection timing control (STC) is used to improve the combustion state under different working conditions. The main function of STC is to advance the fuel injection timing when the low idle speed and low load fuel supply is small to ensure that the combustion can be completed near the top dead center. Advance timing can improve cold start performance, improve idling performance under cold weather conditions, reduce white smoke, and improve diesel engine fuel economy at low load. More importantly, when the diesel engine is at low load, if the timing is not advanced, the combustion will lag too far and the performance will deteriorate sharply, which will cause a large amount of soot to be formed. At the same time, the STC system can also appropriately delay the diesel engine timing under heavy load conditions, providing conditions for improving NOx emissions.
As the PT fuel supply system is adopted, the fuel injected by the nozzle is driven by the camshaft, so the stiffness of the camshaft directly affects the reliability and durability of the diesel engine, so the diesel engine adopts a large-diameter camshaft design. M11 series diesel engines use 76.2mm camshaft journals, N series diesel engines use 63.5mm camshaft journals, and K series diesel engines use 76.2mm camshaft journals, which are larger than ordinary diesel engine camshaft journals, so they have better stiffness. At the same time, the roller-type remote lever cam follower design is adopted, which makes the relative movement between the follower and the cam surface change from sliding friction to rolling friction, from splash lubrication to pressure lubrication, the working and operating stress of the friction pair is reduced, and the lubrication conditions The improvement reduces wear and tear, and improves the reliability and service life of work operation.